A new species of Bryophaenocladius (Diptera: Chironomidae) from Argentina

2011·0.22 MB·

by  Donato, Mariano

ISSN 0373-5680 (impresa), ISSN 1851-7471 (en línea) Rev. Soc. Entomol. Argent. 70 (3-4): 207-212, 2011 207
A new species of Bryophaenocladius (Diptera:
Chironomidae) from Argentina
DONATO, Mariano
Laboratorio de Sistemática y Biología Evolutiva (LASBE). Facultad de Ciencias Naturales
y Museo. Universidad Nacional de La Plata. Paseo del Bosque s/n, B1900FWA, La Plata,
Argentina; e-mail: [email protected]
Una nueva especie de Bryophaenocladius (Diptera: Chironomidae) de
Argentina
 RESUMEN. Se describe y se dibuja el macho de Bryophaenocladius
carolinae sp. nov. La especie puede separarse del resto de las especies
Neotropicales porque posee una punta anal hialina y triangular, con su
punta redondeada; la volsella inferior sub-rectangular y comparativamente
más pequeña; gonostilo ensanchado en su parte media y con una quilla
externa; R finalizando opuesta a la terminación de M ; escama setosa,
4+5 3+4
pseudospinas y peine en la tibia de la pata dos, ausentes. Se brinda una clave de
identificación de adultos machos neotropicales del género Bryophaenocladius
Thienemann.
PALABRAS CLAVE. Orthocladiinae. Sistemática. Neotrópico. Clave.
 ABSTRACT. The male of Bryophaenocladius carolinae sp. nov. is
described and figured. The species can be separated from all other Neotropical
species by having a hyaline, blunt triangular anal point, a comparatively small,
sub-rectangular inferior volsella, gonostylus widened medially with an outer
heel, R ending opposite to end of M , setose squama and absence
4+5 3+4
of comb on middle tibia and pseudospurs. A key to the adult males of the
Neotropical Bryophaenocladius Thienemann is provided.
KEY WORDS. Orthocladiinae. Systematics. Neotropics. Key.
INTRODUCTION and the topic is still in progress (Wang et al.,
2001; 2004; 2006; Du et al., 2011).
The genus Bryophaenocladius Thienemann In this contribution, a new species of the
is distributed worldwide, with the possible genus Bryophaenocladius is described based
exception of Australasia. The genus is on male specimens and the key to adult
very rich with more than 100 species males of the genus for the Neotropical region
recorded (Du et al. 2011). Most species of by Wang et al. (2006) is updated.
Bryophaenocladius appear to be terrestrial
or semi-terrestrial (Cranston et al., 1989) but
Strenzke (1942) recorded immatures of B. MATERIAL AND METHODS
subvernalis (Edwards) from two alpine lakes.
The delimitation of this genus is difficult The specimens were collected with a
since there are exceptions for nearly all sweep net. Microscope slides were made by
diagnostic characters, but in the last ten clearing with 10% KOH; neutralization with
years several revisions clarify its systematics glacial acetic acid; dehydration in 80%, 96%
Recibido: 20-II-2011; aceptado: 30-VII-2011
208 Rev. Soc. Entomol. Argent. 70 (3-4): 207-212, 2011
and 100% ethanol and mounting in Canada Wing length/length of profemur 2.68–2.85
Balsam. Morphological measurements follow [2.68] (2). Coloration blackish brown.
Sæther (1980) in μm rounded to the nearest Head. Antennae with 13 flagellomeres,
5 unless otherwise stated. Measurements are AR 1.36–1.41 [1.41], ultimate flagellomere
given as ranges followed by measurements length 410–450 [410] μm. Temporal setae
of the holotype in square brackets. 10–11 [11], divided in 4 inner verticals, 3
Comparisons with other members of the outer verticals and 3–4 [4] postoculars.
genus Bryophaenocladius were made from Clypeus with 8–14 [11] setae. Cibarial
the original descriptions and revisions. In pump, tentorium, and stipes as in Figure 1.
addition, the new species was compared with Tentorium 135–157 [135] μm long, 22–34
the holotype of Bryophaenocladius nidorum [29] μm wide. Stipes 127–135 [127] (2) long
(Edwards) housed in the Natural History μm, 42–47 [42] μm wide (2). Palp segment
Museum (London, UK) and collection lengths (in μm): 29–34 [29]; 39–49 [39];
material of B. aestivus (Brundin), B. cf. 125–140 [125]; 108–115 [108]; 127–142
astis (Roback), B. flavoscutellatus (Malloch) [127]. Third palpomere without finger-like
and B. pleuralis (Malloch) deposited in the apical extension, without sensilla clavata.
Department of Natural History, Bergen Thorax (Fig. 2). Antepronotum with 6–8
Museum, University of Bergen, Norway. [6] lateral setae. Dorsocentrals 25–29 [25];
The holotypes of the species described by acrostichals 16–17 [16] (2); prealars 8–10
Dr. Manabu Sasa were studied from the [8]. Scutellum with 11–14 [11] setae.
National Museum of Nature and Science Wing (Fig. 3). Microtrichia visible at 100x
Tokyo (Japan), Type Specimen Database magnification. R ending opposite to end
4+5
(http://www.type.kahaku.go.jp/TypeDB/ of M . VR 1.26–1.29 [1.28]. C extension
3+4
diptera),except B. ikiheius Sasa et Suzuki 32–66 [32] μm. Brachiolum with 1–2 [2]
which was not found in this database. setae; R with 11–13 [11]; R1 with 6–11 [6];
The holotype and paratypes of R4+5 with 0–3 [3]. Squama with 6–9 [6]
Bryophaenocladius carolinae sp. nov. are setae.
housed in La Plata Museum, Argentina Legs. Spur of front tibia 64–76 [64] μm
(MLP). long; spurs of middle tibia: 22–27 [22] μm
and 47–54 [47] μm; of hind tibia: 22–32 [22]
μm and 51–69 [51] μm long. Width at apex
RESULTS of front tibia 32–39 [32] μm; of middle tibia
27–42 [34 ]μm; of hind tibia 44 μm. Middle
Bryophaenocladius carolinae sp. nov. tibia without comb. Comb of hind tibia with
11–12 [11] setae, longest 37–44 [37] μm
Diagnosis: The species can be separated long, shortest 20–27 [20] μm long. Lengths
from all other Neotropical species by the (in μm) and proportions of legs in Table I.
following combination of characters: anal
point hyaline, triangular with blunt apex; Hypopygium (Figs. 4–7). Anal point
inferior volsella comparatively small, sub- hyaline, bluntly triangular, 27–31 [31] μm
rectangular; gonostylus widened medially, long, 39–42 [39] μm wide at base; anal point
with outer heel indicated; R ending length/width 1.26–1.52 [1.26]. Tergum IX
4+5
opposite to end of M , squama setose with 8–12 [8] setae, laterosternite IX with 6
3+4
and comb on middle tibia and pseudospurs setae. Phallapodeme 49–61 [51] μm long;
absent. transverse sternapodeme 110–130 [110]
μm long. Virga 22–27 [25] μm long, with
Male (n = 2–3) two spines. Gonocoxite 194–206 [194] μm
long, inferior volsella sub-rectangular with a
Total length 2.45–2.65 [2.45] mm (2). dorsal lobe with 5-6 [5] apical setae and a
Wing length 1.34–1.58 [1.34] mm. Total ventral lobe with 2-3 [2] apical setae (Figs.
length/wing length 1.72–1.83 [1.83] (2). 6–7); ending 95–115 [100] from apex of
DONATO, M. A new species of Bryophaenocladius 209
Table I. Lengths (in μm) and proportions of legs of Bryophaenocladius carolinae n. sp. (male) (n = 2–3).
Abbreviations: Femur (Fe); Tibia (Ti); Tarsomeres 1-5 (Ta ); Leg Ratio (LR), ratio of metatarsus to tibia;
1-5
Beinverhältnisse» (BV), combined length of femur, tibia, and basitarsus divided by combined length of
tarsomeres 2-5; «Schenkel-Scheine-verhältnis» (SV), ratio of femur plus tibia to metatarsus.
Fe Ti Ta
1
P 500–540 [500] (2) 610–730 [610] 360–460 [360]
1
P 560–670 [560] 580–700 [580] 270–330 [270]
2
P 590–700 [590] 690–850 [690] 380–460 [380]
3
Ta Ta Ta
2 3 4
P 210–270 [210] 160–200 [160] 120–140 [120]
1
P 150–180 [150] 110–140 [110] 90–100 [90]
2
P 210–260 [210] 160–210 [160] 100–120 [100]
3
Ta5 LR BV
P 80–100 [80] 0.47–0.64 [0.47] 2.42–3.14 [3.14] (2)
1
P 80–90 [80] 0.46–0.55 [0.55] 2.87–3.33 [2.91]
2
P 90–100 [90] 0.54–0.56 [0.55] 2.91–2.98 [2.96]
3
SV
P 2.86–4 [4] (2)
1
P 3.29–4.26 [3.29]
2
P 3.31–3.37 [3.37]
3
Figs. 1-3. Bryophaenocladius carolinae sp. nov. Male adult. 1, Tentorium, stipes and cibarial pump; 2,
thorax; 3, wing.
210 Rev. Soc. Entomol. Argent. 70 (3-4): 207-212, 2011
Figs. 4-7. Bryophaenocladius carolinae sp. nov. Male adult. 4, Hypopygium dorsal view; 5, hypopygium
with tergite IX removed, right ventral view, left dorsal view; 6, inferior volsella dorsal view; 7, inferior
volsella ventral view.
gonocoxite; distance from apex of gonocoxite Type material. ARGENTINA. Buenos
to apex of inferior volsella 110–122 [110]; Aires: Holotype male, MLP number 5312/1:
ratio of “inferior volsella ending from apex of Los Hornos, 34º 57’ 32’’S- 58º 00’ 57’’W, 16-
gonocoxite/length of gonocoxite” 0.47–0.56 IV-2005, sweep net, M. Donato leg. (MLP).
[0.52]. Gonostylus 96–105 [96] long, widest Paratypes, MLP numbers 5312/3–4: 2 males,
medially and with a slight angulate subapical same data as the holotype.
heel; crista dorsalis absent; megaseta 10–12
[10] long (9). HR 1.93–2.1 [2.02]; HV 2.55– DISCUSSION
2.7 [2.55] (2).
The genus Bryophaenocladius is one
Etymology. Dedicated to my wife of the largest genera in the subfamily
Carolina, for her patience and support. Orthocladiinae. The systematics and
DONATO, M. A new species of Bryophaenocladius 211
taxonomy of this genus is based mainly states found for this character are anal point
on males with a few exceptions that are long with rounded apex [e.g. B. aestivus
based on females and the knowledge of its (Brundin)]; anal point pointed triangular
immature stages is scarce. The variation in [e.g. B. flexidens (Brundin)]; anal point wide,
the taxonomic characters is large, mainly trapezoidal [e.g. B. inconstans (Brundin)];
in the shape of the hypopygium. Wang anal point bluntly triangular [e.g. B. scanicus
et al (2006) pointed out that the species (Brundin)]; anal point sharply triangular (e.g.
defined as belonging to Bryophaenocladius B. parinberbus Wang et Du) and anal point
are based on a combination of characters subtriangular (e.g. B. usambarensis Andersen
and they also considered that probably this et Schnell). The other character states found
character variation could give rise to split were anal point small triangular (present in
the genus into several genera or subgenera B. togatenuis Sasa et Okazawa) and anal
in the future when the revision of the genus point absent (present in B. ikiheius Sasa et
is completed. Suzuki).
The new species here described was The combination of characters anal point
established after a comparison with the bluntly triangular and hyaline, gonostylus
rest of the species of the genus from their widened medially, virga present and finger-
original descriptions or from a revision, as like apical extension on palpomere 3 present
well as after the study of their holotypes or in Bryophaenocladius carolinae are shared
collection material. In this way, 92 species with three species of the 92 species studied
of the genus Bryophaenocladius were of the genus. The species B. digitatus Sæther
compared with B. carolinae and studied is clearly distinguished from B. carolinae
in order to account for the variation in the by the presence of a weak comb at apex of
taxonomic characters pointed out by Wang middle tibia, wing punctuation coarse and
et al. (2006). The taxonomic characters inferior volsella digitate with few curved
were divided into two groups based on setae dorsally. The species B. kobayashii
their importance in delimiting species. As Makarchenko et Makarchenko differs from
a result, the most important characters used B. carolinae by the presence of a rounded
to define the Bryophaenocladius species inferior volsella. The species B. xinglongensis
are the shape of the anal point, the shape Du et Wang is clearly distinguished from the
of inferior volsella, presence or absence new species here described by the presence
of virga, shape of gonostylus, the presence of a not obvious and setose inferior volsella
and different degree of development of and R ending distal to end of M .
4+5 3+4
the crista dorsalis, presence or absence of
the finger-like projection on palpomere 3 Key to males of the genus
and wing punctuation. Other characters Bryophaenocladius from the Neotropical
used in the species diagnosis, although region (modified from Wang et al. 2006)
less important, are the presence or absence
of wing anal lobe, number of setae on R1 1. Palp with 4 short palpomeres .....................
vein, different degree of development of ....................................... Bryophaenocladius
acrostichal setae, length of Costal extension, carus (Roback). Panama, Brazil
length of megaseta, presence or absence - Palp with 5 well-developed palpomeres ...
of pseudospurs, presence or absence of a
.................................................................. 2
comb at apex of middle tibia, presence or
absence of oral projections in sternapodeme,
2. Third palpomere with digitiform
number of palpomeres and AR. Among the
projection ..................................................
characters mentioned above as the most
.................................... Bryophaenocladius
important, the character shape of anal point
was found as a very good character since it simplex Wang, Andersen et Sæther. Mexico
has six well defined character states and only - Third palpomere without projection ..........
two particular character states. The character .................................................................. 3
212 Rev. Soc. Entomol. Argent. 70 (3-4): 207-212, 2011
for their comments and suggestions that
3. Inferior volsella digitiform; mid leg have improved this paper. Special thanks
with weak comb .............................. to Dr. Gustavo R. Spinelli, specialist of
Bryophaenocladius digitatus Sæther. Mexico Ceratopogonidae of the Museo de La Plata,
- Inferior volsella rounded or sub-rectangu- who examined the type of B. nidorum at the
lar …………………………….............…. 4 Natural History Museum in London.This
paper was supported by grant PIP N° 0729
4. Pseudospurs absent …... Bryophaeno- (CONICET).
cladius carolinae sp. nov. Argentina
- Pseudospurs present …………………… 5
LITERATURE CITED
5. Megaseta simple; transverse sternapodeme
1. CRANSTON, P. S., D. R. OLIVER & O. A. SÆTHER. 1989. The
lacking oral projections ……………......... adult males of Orthocladiinae (Diptera: Chironomidae)
Bryophaenocladius humerosus Wang, of the Holarctic region - keys and diagnoses.
Entomologica Scandinavica Supplement 34: 165-352.
Andersen et Sæther. Mexico 2. DU, J., X. H. WANG & O. A. SÆTHER. 2011. Redescriptions
- Megaseta with several teeth; transverse of species of Bryophaenocladius Thienemann, 1934
(Diptera: Chironomidae) described by Brundin (1947).
sternapodeme with pronounced oral
Zootaxa 2743: 40-48.
projections .................................................. 3. SÆTHER, O. A. 1980. Glossary of chironomid morphology
.................. Bryophaenocladius pichinensis terminology (Diptera: Chironomidae). Entomologica
Scandinavica Supplement 14: 1-51.
Wang, Andersen et Sæther. Mexico 4. STRENZKE, K. 1942. Terrestrische Chironomiden XII:
Bryophaenocladius subvernalis Edw. (Chironomiden
aus dem Lunzer Seengebiet IV). Zoologischer Anzeiger
137: 177-185.
ACKNOWLEDGEMENTS 5. WANG, X. H., O. A. SÆTHER & T. ANDERSEN. 2001.
Afrotropical Bryophaenocladius Thienemann, 1934
(Diptera, Chironomidae). Studia Dipterologica 8: 447-
I greatly acknowledge Trond Andersen 462.
and Humberto Mendes for their hospitality, 6. WANG, X. H., T. ANDERSEN & O. A. SÆTHER. 2006.
Neotropical Bryophaenocladius Thienemann, 1934
kindness and help during my visit to Bergen.
(Diptera: Chironomidae). Studies on Neotropical
In addition, I wish to thank Trond Andersen Fauna and Environment 41: 19-32.
for his comments and suggestions on this 7. WANG, X. H., Z. LIU & J. H. EPLER. 2004. New species
of Bryophaenocladius Thienemann from the Nearctic
work and his advice to improve my drawings.
Region (Diptera: Chironomidae: Orthocladiinae).
Also thanks to two anonymous reviewers Zootaxa 581: 1-10.